RESUMO
BACKGROUND: The ideal installation technique or implant macrogeometry for obtaining an adequate osseointegration in low-density bone tissue follows a challenge in the implantology. AIMS AND OBJECTIVE: The aim of the present study was to evaluate the behavior of three osteotomy techniques and two implant macrogeometries in two low-density polyurethane blocks. The insertion torque (IT), initial stability, pullout resistance, and weight of the residual bone material deposited on the implants were assessed. MATERIALS AND METHODS: A total of 120 implants with two different macrogeometries were used. They were divided into six groups according to the implant macrogeometry and the drilling technique performed (n = 20 implants per group). The implants were installed in polyurethane blocks with pounds per cubic foot (PCF) 10 and PCF 20 densities. The IT, initial stability, pullout resistance, and weight residual bone were measured. RESULTS: Differences were found in the values referring to the macrogeometry of the implants and the type of osteotomy performed. In all groups, the initial stability of the PCF 10 blocks was quite low. The undersized osteotomies significantly increased the values measured in all tests in the PCF 20 density blocks. CONCLUSIONS: In conclusion, even when a modified (undersized) osteotomy technique is used, implants inserted in low-quality bone (type IV) can present problems for osseointegration due their low initial stability and bone resistance. However, the modification in the implant macrogeometry (with healing chambers) presented more quantity of bone on the surface after the pullout test.
RESUMO
BACKGROUND: The topographical surficial characteristics and properties of materials can induce different cell reactions regarding the viability and adhesion according to the recent patents. The aim of this in vitro experimental study was to evaluate the viability and adhesion of fibroblastic cells seeded on titanium disks with different surface topography. In addition, we revised all patents related to surface treatment of dental implants. METHODS: Fibroblast cells were cultured on 6 surface models: mA disks corresponding to titanium surfaces without additional treatment (machined surface) were compared with mB disks, where surfaces were sandblasting etching using aluminum oxide; mC disks where titanium oxide was used for sandblasting etching; mD disks where triple acid conditioning was used; mE disks with laser treated surface; and mF disks which were made of titanium powder by a sintering process. Different surfaces were analyzed using an optical laser profilometer and SEM analysis. To evaluate cell viability on different disc surfaces, a fibroblast cell line derived from monkey kidney (VERO) was in vitro cultured on treated disks surface and cell viability assays were performed to compare growth of fibroblastic cells. Then, the adhesion of the cells was tested by washing procedure. RESULTS: The disks mA, mB, mC and mD less pronounced rugosities were observed and, disc in the mE and mF disks displayed a deeper pronounced surface. The cell viability and adhesion analysis showed significant higher levels on titanium disks surface obtained by the mF method. CONCLUSION: Our analysis showed that the surface morphology of titanium disc, independent of the roughness parameters, affects cell viability and adhesion differentially, since a higher percentage of viable and attached cells were observed on the mF disks in comparison with the other evaluated surfaces.